.contentBody{
  width: 100%;
  /*****calc 函数中，三个参数需要有空格*****/
  min-height: calc(80vh - 100px);
  box-sizing: border-box;
  overflow: hidden;
}

.content{
  margin:auto;
  width:300px;
  height: 300px;
  border-radius: 300px;
  /* background-color: black; */
  background-image: url('../images/bg-icon.png');
  background-position:center ;
  background-size: 100%;
  background-repeat: no-repeat;
  background-origin: content-box;
  animation: my-rotate 5s linear infinite;
}

@keyframes my-rotate{
  from {
    transform: rotate(0deg);
  }to{
    transform: rotate(360deg);
  }
}